In the case of many of the the moulds, e.g. when combining water jacket and bed moulds, between individual portions or mould shapes there are very narrow gaps or clearances in which, following the production of the sand moulds or cores, burrs can be left behind, e.g. in the vicinity of the parting line between a lower tool and an upper tool in which the corresponding moulds or cores are produced. For automation reasons jointly produced water jacket and bed cores must be immediately assembled. It is then difficult to have access to the gaps in order to remove the burrs, particularly if this is also to take place in a completely automatic manner.